#!/bin/sh
# pacsize -- display package sizes
#
# Copyright (C) 2014 Pierre Neidhardt <ambrevar@gmail.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

################################################################################
## Helper functions.

calc_total () {
    awk '{
    total += $1
    print
}
END {
    printf ("%7s KIB TOTAL\n", total)
}'
}

remove_duplicates () {
    awk '! table[$0]++'
}

usage() {
    cat <<EOF
Usage: ${1##*/} [OPTIONS] PACKAGES
       ${1##*/} -a [OPTIONS]

Display package sizes. Duplicates are removed if any. Output can be sorted by
name or size. A grand total can be printed at the end. Both the sync and the
local databes can be used for lookup.

Options:

  -a: All installed packages. Implies -Q.
  -h: Show this help.
  -n: Output is sorted by name.
  -Q: Use local database. It speeds up queries and allows displaying
      size of local packages not available in repos.
  -S: Use sync database. It is slower but allows to display size of
      non-installed packages.
  -s: Output is sorted by size.
  -t: Print total.

Examples:

  ${1##*/} -ast
    Convenient way to keep track of big packages.

  ${1##*/} -Q \$(pactree -ld1 linux)
    Print the size of linux and all its direct dependencies.

  ${1##*/} -Qst \$(pacman -Qdtq)
    Print a grand total of orphan packages, and sort by size.
EOF
}

db="Q"
opt_sort=false
opt_all=false
opt_total=false

while getopts ":ahnQSst" opt; do
    case $opt in
        a)
            opt_all=true
            db="Q" ;;
        h)
            usage "$0"
            exit ;;
        n)
            opt_sort="sort -uk3" ;;
        Q)
            db="Q" ;;
        S)
            db="S" ;;
        s)
            opt_sort="sort -un" ;;
        t)
            opt_total="calc_total" ;;
        ?)
            usage "$0"
            exit 1 ;;
    esac
done

shift $(($OPTIND - 1))

################################################################################
## All-packages mode. We use a dedicated algorithm which is much faster than
## per-package mode.
if $opt_all; then
    DBPath="$(awk -F = '/^ *DBPath/{print $2}' /etc/pacman.conf)"
    [ ! -d "$DBPath" ] && DBPath="/var/lib/pacman/"
    [ ! -d "$DBPath/local/" ] && exit

    awk '/^%NAME%/ {
    getline
    pkg=$0
}
/^%SIZE%/ {
    getline
    size = $0 / 1024
    printf ("%6s KiB %s\n", size, pkg)
}' "$DBPath"/local/*/desc | ($opt_sort || cat) | ($opt_total || cat)
    exit
fi

################################################################################
## Per-package mode.
if [ $# -eq 0 ]; then
    echo "Missing argument." >&2
    usage "$0"
    exit 1
fi

if ! command -v pacman >/dev/null 2>&1; then
    echo "'pacman' not found." >&2
    exit 1
fi

## Locale.
LC_NAME="$(gettext pacman "Name")"
LC_SIZE="$(gettext pacman "Installed Size :" | sed 's/ *: *$//')"

## We use external variable for awk to fit current locales. In the following
## command, we strip the decimals. This makes output lighter.
pacman -${db}i "$@" 2>/dev/null | awk -F ": " \
    -v pkgsize="$LC_SIZE" -v pkgname="$LC_NAME" \
'$0 ~ pkgname {
    pkg = $2
}
$0 ~ pkgsize {
    gsub (/[\.,].*/, "")
    printf ("%7s KiB %s\n", $2, pkg)
}' | ($opt_sort || remove_duplicates) | ($opt_total || cat)